Hi, I just started a Linux kernel on the board and wanted to let it fail-boot, but somehow it did find a root partition at SPI offset 0x600000 (mtd2) and booted properly ! Was there a root-fs (jffs2) pre-flashed, because I cannot remember that I did flash it !
There is a initramfs based root file system attached to the Linux kernel image by default configuration. Linux always loads rootfs from the intiramfs in this case. If you wish to fail-boot a Linux kernel, please remove the initramfs support from both the buildroot and Linux kernel and rebuild the uImage.